Gyro precessing system



Aug. 26, 1952 G. F. ROUSH GYRO PRECESSING SYSTEM Filed Jan. 31, 1948 INVENTOR. EU) E HUU5H fliromwsr- Patented Aug. 26, 1952 GYRO PRECESSING SYSTEM Guy F. Roush, Montclair, N. J., assignor to Bendix Aviation Corporation, Tetcrboro, N, .L, a

corporation of Delaware Application January 31, 1948, Serial No. 5,539

14 Claims. 1

This invention relates to gyroscopes, and more particularly to a system for providing the necessary precessional torques to the gyroscope upon .departure of the spin axis thereof from a reference axis.

An object of my present invention is to provide a gyro precessing system whereby torques are periodically applied to. a gyroscope to return the spin axis thereof to a reference axis upon departure therefrom.

Another object of my invention is to provide a gyro precessing system of the general character indicated in which the torque applied thereto is in response to electrical signals, the phase and amplitude of the: signals being dependent. on the direction and extent of spin axis drift.

A further object of this invention is to provide a gyro precessing system of the character indicated in which the time intervals of applying the precessional forces to the gyroscope are varied to control the return rate of the spin axis to the reference axis upon departure therefrom.

Still another object of the present invention is to provide a gyro processing system of the character indicated which shall consist of few and simple parts, relativel inexpensive to manufacture, positive and accurate in its operation, which shall have a large variety of applications andyet be practical and enicient to a high degree inuse.

Other objects of this invention will in part be obvious, andin part hereinafter pointed out.

In the accompanying drawing forming a part of this specification in which one of the various possible illustrative embodiments of this invention is shown in a schematic wiring diagram, the numeral I designates a control circuit interconmeeting a signal source I I mounted on a gyrovertical- (not shown) and two torque motors l2 and I 3 adapted to apply a precessional torque about the major and minor axes of the gyroscope respectively, in response to the signals of said source.

The signal source H comprises a laminated ring core M of highly permeable material mounted concentrically with the spin axis of the gyroscope. Two pairs of poles l5 and I6 are provided, each having a winding l'l thereon and connected in pairs in series opposition. A rolling mass t8 is provided in the form of a. steel ball, the: movement thereof being limited upon departureof the spin axis of the gyroscope from its vertical position by a non-magnetic ring or cup I9. A circular energizing winding 20, here shown as acoil, is concentricwith the core Hi and in inductive relation with the four windingsthereon,

An energizing current flowing through the pri v mary winding 20 will induce a voltage in eachofthe windings I1. Since a pair of the windings are connected in series opposed relation, the voltages induced in each pair of windings will cancel each other. When the spin axis of the gyroscope is in its vertical position, the ball [8 will be concentric with the spin axis and occupy a position midway between the poles l5 and IS. The flux linkages of the energizing coil 20 and the windings I! will be unaffected by the mass of the ball; or if affected, the effects being equallydistributed so that the voltages induced in the windings H are equal. Upon a departure of the spin axis from the vertical position the ball I 8 will roll within the ring I 9' to seek the lowermostposition. The magnetic balance heretofore'ha'd" is thus destroyed. The voltages induced the windings I! are no longer equal. A signal voltage will thus be provided by each of the pairs of'coils equal to the algebraic sum of the two voltages'. The phase of the signal voltage, as well'as its amplitude will be dependent upon the proximity of the rolling mass to the poles. A signal voltage is thus obtainable dependent upon the departure of the spin axis from the axis of reference,

A current flowing through the energizin coil 20 will" attract the steel ball l8 and will hold the same against the ring I9. The coil 2-0 is ther'e,-. fore intermittently energized to allow the mas?- netic field of the winding to decay permitting the ball to roll in response to the tilt of the gyro spinaxis. To this end, therefore, there is provided a re: laxation oscillator circuit generally designatedby thenumeral 2-5 and comprising two triodes 26' and 21'. The triode 26 comprises an indirectly heated cathode 29, a control grid 30' and a plate. 3|, while the triode 21 comprises a cathode 33;. a control grid 34 and a plate 35. The plate 31- is connected; by a lead 36 through resistors 31 and; 38 to the B-|- supply, andby a lead 40- to anon-.- denser 41. The plate 35- of thetriode- 21- is con-1' nectedby a lead 43 through the coil of a--relay i4 and through the resistor 38 to the 13+ supply, a condenser 45 being shunted across the relay coil. The plate 35 is further connectediby the lead 43' and a lead 41' through a, condenser 48-- to the grid 30 of the tube 26. The grid 30, is,f1l1!-'- ther connected by a lead 49 through the series; connected resistors 50, 5| and 52 to, ground. A. resistor 53 shunted by a condenser 545 is con-' nected: between ground and the: grid 34? by alead 3 56. The cathodes 29 and 33 of the two tubes are interconnected by a lead 58 to the junction of resistors 52, 53 and to ground.

A small positive charge on grid 30 will start the oscillations, the charge being amplified by both tubes 26 and 21 and a portion of the amplifleld voltage will .be fed back to grid 30 via leads 43, 41 and condenser 48. The grid potential of tube 26 will suddenly rise to a positive value, while the grid voltage of tube 21, will suddenly go more negative than cut-off. Amplification will cease and momentarily one tube 26 will draw a heavy plate current while the other tube 2'! draws no plate current. The leakage through the gridleak resistances 5053 will gradually bring the grid voltages back to normal at which point amplification will again take place, this time the grid 34 goin positive and grid 38 negative.

The oscillations are determined by the values of the grid-leak resistances 50-53 and the grid condenser capacities 48 and 54. Changes in the frequency of the oscillations may therefore be made by grounding the resistors 50 and 5| as will hereinafter be described.

The relay coil 44 connected into the plate circuit of tube 21 controls a switch arm 68 normally engaging a stationary contact 6|. The arm 60 is connected to the grounded secondary winding 62 of a transformer 63, the primary 84 of which is connected across a suitable source of alternating current supply. The fixed contact 6| is connected by a lead 65 through the energizing coil 20 of the signal source I I. The relay 44 is energized each time the plate 35 draws current in the cycle described. Energization of the relay will open the circuit of the energizing coil 20 to permit the ball to roll freely upon tilt of the gyro spin axis as herein described.

The frequency of the pulses applied to the energizing winding 20 is controlled by grounding the resistances 50 and/ or 5| so that a predetermined erection rate may be obtained. While the grounding of these grid resistors may very readily be done by means of a multi-pole switch, I have provided a relay circuit to time the sequences in which the erection rates are varied.

To this end, the leads I and II connected to the resistors 50 and respectively, are connected into a relay circuit comprising the relays I2, 13 and 14. The relay I2 controls a normally open switch arm I5 connected to ground and adapted to engage a fixed contact I5 connected to the lead 'II. The relay 13 also controls a normally open switch arm I! connected to ground and adapted to engage a fixed contact 18 connected to the lead I0. The relays I2 and I3 are connected by a lead I8 to plus power supply. The relay I2 is connected by a lead 80 through a normally closed switch 8| to a fixed contact 82 of relay I4. Relay I3 is further connected by a lead 83 to a second fixed contact 84 of the relay I4. A grounded switch arm 85 is adapted to engage the fixed contact 84, and disengage therefrom and engage the contact 82 upon energization of the relay I4. The relay I4 is of the time delay type and is connected to ground and by a lead 86 through a normally open switch 81 to plus power supply.

The relay circuit as illustrated in the accompanying drawing shows the relays I2 and I4 deenergized. The grid leak resistors 50, 5|, and 52 are connected into the circuit of tube 26, while resistor 53 is connected into the circuit of tube 21. With the circuit connections as illustrated the energizing coil 20 is pulsed approximately 0.5 cps., giving an erection rate of about 2.5 degrees per minute.

The relay I4 will be energized upon closing the open switch 81. The relay 14 being of the time delay nature, will lift the switch arm to engage the contact 82, after a time interval of perhaps five minutes. During this time interval, the switch arm 85 engaging the fixed contact 84 will complete an energizing circuit through the relay I3. The energized relay I3 will lift the switch arm 11 into engagement with the fixed contact I8 to ground the resistor 58 through the lead III. The grid leak resistance of tube 26 now comprises the grounded resistor 50. The frequency of the oscillator circuit is thereby varied to provide an erection rate of 22.5 degrees per minute. Thus in starting the operation of the erection system for the gyro-vertical a comparatively large erection rate is provided.

After the time interval set for the relay I4 has elapsed, in which time the gyro will have been brought up to the desired speed and erected, relay '13 will be deenergized and relay 12 will be energized through the lead 80. Energization of the relay I2 will close the switch arm I5 and fixed contact I6 to ground resistors 50 and 5I through the lead 'II. The grid leak resistance now in the circuit of the tube 26 comprises the two resistors 58 and 5|. A smaller erection rate of approximately 8 degrees per minute is thus provided five minutes after the closing of switch 81. The erection rate provided is desirable under normal operating conditions.

From the circuit illustrated in the accompanying drawings, the opening of switch 8| will break the energizing circuit for therelay I2. Switch 8| is adapted to be opened by the gyroscope when the bank attitude exceeds 3 degrees to provide the minimum erection rate to avoid throwing the gyro-vertical off.

The intermittent signals induced in the pickup windings I! are impressed on an amplifier and phase discriminator section of the control circuit and thence applied to the respective torque motors I2 and/or I3.

The windings on poles I6 in alignment with the minor axis of the gyroscope are grounded at one end, and connected by a lead I00 to a control grid IOI of a double triode I02. The windings on poles I5 are connected by a lead I03 to the second control grid I04 of the tube I02. The indirectly heated cathodes I05 of the tube are interconnected by a resistor I06 provided with a grounded tap I01. Condensers I08 interconnecting leads I00 and I03 and the ground complete the input circuits for the tube I02.

The plate I09 of the tube I02 is connected by a lead II!) to a phase discriminator circuit comprising a duo-triode I I2 and a magnetic reactor H3. The lead H0 is connected through a condenser II4 and a resistor II5 to the control grid H6, and by a lead II'I through a resistor II8 to the second control grid IIO of the tube I I2. The plate I09 is further connected by the lead I I0 and a lead I20, through a resistor |2| to 13+ supply. The lead I I0 is connected by a lead I22 through a resistor I23 to bias supply voltage I24.

The cathodes I25 of the tube II2 are interconnected by a resistor I26 having a variable tap I2! connected by a lead I28 to ground. The plate I30 of the tube is connected by a lead I3I through the magnetic reactor II3 to the power supply I32, while plate I 33 of the tube is similarly connected by a lead I34 to the power supply.

The magnetic reactor I I3 comprises a soft iron spasms 5. core (not shown) having two. primary windings Mm and MI thereon connected in series byza lead In and connected by leads Into the. source or supply- 132; and'two sec'ondary windings m and M 'con-n'ectedin: series op osition by a: lead ME the ends of windings [M and I45 form= the output of the reactor and'a're connected by the leads I41 to the variable phase H3101 the two phase induction motor I2. saturating windings M9 and. I50 are alsoprovided on the coreot the reactor and are connectedby the respective leads I31 and I342 to the'plates I30= and I33: of the tube H2; Theother ends-ofthe saturating windpigs areconnected by the leads: I.5I. and. I52, respectively, to the secondary winding I153 of a transformer I"54.. The primary winding. [55 at the transformeris. connected across the: leads IE3: of. the power supply? I32 The: voltage applied. to? the plates I30: and. I 33' will be .180 degrees: out-of r'nhase due: to the groundedcenter-tap of the secondarywinding. of the transformer I154; Thetube-beingjbiased; to ClltrOff, the section of the tube which '-operates w'ill. depen'dupon:v the polarity of the amplified displacement signal impressed on the respective grids I I6 and I I9. With no signal on the control grids. no plate current will flow through the saturating windings I49 and I50 of the. reactor H3. The voltageinducedin the secondary windings I; and I45 will be equal. The; windings beingconnected in series opposed relation, the induced: voltage-in each winding will cancel each other, with the result that no current. will flow in the output leads I41.

Upon. departure of thegyro. spin axis from the reference axis. assuming the departure to be in the correct plane, a displacement signal will be induced-in the windings on poles I6. This displacement.- signal will. thereupon be amplified by the upper section of tube I02 and applied to the grids of the tube H2. If we assume the spin axis departure was along the minor axis of. the gyroscope and upward when viewing the drawings, we'may assume the polarity of such a signal to. be such as to operate the upper section ofthe discriminator tube H2. In. this event, plate current will flow throughthesaturating winding I40 to. saturate the core of thereactor. H3 The inductive. balance heretofore had isdestroyed, permitting. a. current to flow in the outputleads Mile The induction motor I1. having an energized phase I58 and the variable. phase I48 now being momentarily energized, will. operate to provide. a torque impulse about the major axis of the gyroscope. I torque is-applied will depend. upon the phaseof the voltage applied across the variable phase I48- by the reactor 3. The phase of. the reactor voltage.- will be, as already indicated, dependent. upon the phase of thedisplacement signalv inducedin the pick-off windings on the minor poles I0.

If we assume the departure of the spin axis along: the minor axis to be downward whenview ing the drawing, thephase of thesignal induced: in the windings on poles I6 would be such as tooperate the lower section of the tube M2 to reverse the output voltage polarityof the reactor I:I3- from that given in the example above; The

motor I2 will therefore apply a precessional.

torque to the gyroscope. which is also opposite in direction.

A departure of the gyro spin axis along. the major axis of the gyroscope will inducea signal in the. windings about the. poles I5. This dis-- The direction in which this,

7a ofthe gyroscopjei'spin axis from a reference; axis,

placement-z signal will: be. amplified by: the. lower section of tube I02- and; applied through similar circuits tothevariable phase "59' ofthe motor 13'. The plate 1-60 of the amplifier tube. I02; of. the major axis? signal channel is connected in the samemanher'asplate I09 to a discriminator. tube I61 by the platev lead "52.. The plates I63 and IE4 of: the tube: I61 are connected respectively-by loads ('65 and I66" to a magnetic-reactor I61. The output leads I68 of. the reactor IB'I' are 0011:- nectedacrossithe variable: phase I69 of the motor I3; while.- the fixed. phase II0 of. themotor 18.0011.- nected across a suitable power source. The operation of: the major axis-signal channelis the same. as that described in. connection. with. the; minor axis of the gyroscope;

By adjustment of the groundedcont'act IZ'I on the cathode resistor I26 of the discriminator tube lliitheerection rate of the gyroscope spin axis from. a certain departure along the minor. axis thereof may be equalized, and: similarly the erecs tion rate'of the-spin axis from a departure along.- the major axis may be equalized by adjusting the;

grounded contact ofthe corresponding cathode resistor of tube IBI. The adjustment of the grounded contact I01 on cathode resistor I-BG-of tube I02 may then be made to equalize: the erection. rate in the major and. minor axes.

It-will be apparentin the examples given, that the departure of. the gyroscope spin axis may be inplanes-other than those indicated. The rolling ball IB- will vary the impedance of both magnetic circuits to cause a displacement signal to; be induced in each pair of the windings on poles. I5- and- I6; Both channels of the control circuit: I0 will thus be operated to provide momentary torques about both of the gyroscope axes.

In. resumethen, there isprovided intermittent displacement signals upon departure of the gyroscope spinaxis-from the reference axis. The intermittent signals arev provided by thepulsingof the energizing winding 20 upon operation of. the relaxation. oscillator 26, 21, and. the changein impedance of the magnetic circuit linking the. energizing winding 20- and the pick-01T- windings I? by the rolling ball I8. The time oh and time on of the pulsing circuit for the energizing wind-- ing 20 may be controlledby the operation. of the relays 14' and. I2, I3 in changing the grid leak resistances of the oscillator circuit.

The intermittentdisplacement signals. thus pro. vided. are amplified by the tube I02. A. phase discriminator circuit I12, I6'I. then. separates the amplified. displacement signals according to phaseand through amagnetic reactor I I3, I61, applies a voltage to the torque producing motors I2. and I3 to. provide the precessional impulses to the gyroscope about the proper axis thereof.

There isthus provided a novelgyroprecessing system which the several. objects of this inventi'on are achieved and which. is Well adapted to meet the conditions of practical. use.

As various embodiments may be made of the above invention, and as, various changes may be made in the embodiment above set forth, it will. be. understood that all matter herein set forth, or shown in the accompanying drawing is to: be. interpreted. as illustrative and not in: a. limiting.

sense.

Having; thus described my invention, I claim as. new and desire to-secure by LettersPatent:

l. Agyro processing system comprising a gyroscope, means onsaid-gyroscope adapted to de-- elop-intermittent signal voltages'upon departure.

a balanced circuit comprising inductive means adapted to be unbalanced by sai signal voltages, and means operative upon the unbalance of said circuit to intermittently precess said gyroscope.

2. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope adapted to develop an intermittent signal voltage upon departure of the gyroscope spin axis from a reference axis, a balanced circuit comprising inductive means adapted to be unbalanced by said signal voltage, and means operative upon the unbalance of said circuit to provide intermittent precessing torques to said gyroscope.

3. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope adapted to be intermittently energized to develop intermittent signal voltages upon departure of the gyroscope spin axis from a reference axis, a balanced circuit comprising inductive means adapted to be unbalanced by the intermittent signal voltages, means operative upon an unbalance of said circuit to precess said gyroscope, and means for varying the rate at which said element is intermittently energized.

4. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope adapted to be intermittently energized to develop signal voltages responsive to the departures of the gyroscope spin axis from a reference axis, a balanced circuit comprising inductive means adapted to be unbalanced by said signal voltages to precess said gyroscope, means for varying the rate at which said element is intermittently energized, and means for providing a timed sequence in varying the energization rate of said element.

5. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope, a delay oscillator intermittently energizing said element to provide intermittent signal voltages upon tilt of the gyroscope spin axis from its vertical position, a balanced circuit comprising inductive means adapted to be unbalanced by said signal voltages and a motor connected to said inductive means and operative upon an unbalance of said circuit to apply a precessing torque to the gyroscope.

6. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope, a relaxation oscillator intermittently energizing said inductive element to provide intermittent signal voltages responsive to the tilt of the gyroscope spin axis from its vertical position, a magnetic reactor whose reactance varies in accordance with said signal voltages, and means responsive to reactance change of said magnetic reactor to apply an erecting torque to said gyroscope.

7. 'A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope, a relaxation oscillator intermittently energizing said inductive element to provide intermittent signal voltages responsive to the tilt of the gyroscope spin axis from its vertical position, means for varying the impedance of the grid circuit of said oscillator to vary the energization rate of said inductive element, a magnetic reactor whose reactance varies in accordance with said signal voltages, and means responsive to reactance change of said magnetic reactor to apply an erecting torque to said gyroscope.

8. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope, a relaxation oscillator intermittently energizing said inductive element to provide intermittent signal voltages responsive to the tilt of the gyroscope spin axis from its vertical position, means for varying the impedance of the grid circuit of said oscillator to vary the energization rate of said inductive element, a relay circuit for timing the sequence in which the impedance of the grid circuit is varied, a magnetic reactor whose reactance varies in accordance with said signal voltages, and means responsive to reactance change of said magnetic reactor to, apply an erecting torque to said gyroscope.

9. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope, a relaxation oscillator intermittently energizing said inductive element to provide intermittent signal voltages responsive to the tilt of the gyroscope spin axis from its vertical position, means for varying the grid-leak resistance of said oscillator to vary the energization rate of said inductive element, a relay circuit for timing the se quence in which the grid leak resistance is varied, a magnetic reactor whose reactance varie in accordance with said signal voltages, and means responsive to reactance change of said magnetic reactor to apply an erecting torque to said gyroscope.

10. A gyro precessing system comprising a gyroscope, an inductive element adapted to develop a signal in response to the tilt of the gyroscope spin axis from its vertical position, a balanced circuit comprising inductive means responsive to said signal and unbalanced thereby, means responsive to the unbalance of said circuit to apply an erecting torque to said gyroscope, means for varying the erection rate of said gyroscope, and means for timing the sequence of the erection rates.

11. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope, means for intermittently energizing said inductive element to provide intermittent signal voltages responsive to the tilt of the gyroscope spin axis from its vertical position, means responsive to said intermittent signals to provide erecting torque impulses to said gyroscope, means for varying the energization rate of said element to provide diilerent erection rates for said gyroscope, said last means including a switch operative upon deviation of the gyroscope spin axis from the vertical axis a greater degree than a predetermined maximum to provide a minimum erection rate for the gyroscope.

12. A gyro precessing system comprising a gyroscope, an inductive element on said gyroscope, means for intermittently energizing said inductive element to provide intermittent signal voltages responsive to the tilt of the y oscope spin axis from its vertical position, means responsive to said intermittent signals to provide erecting torque impulses to said gyroscope, means for varying the energization rate of said element to provide different erection rates for said gyroscope, said last means including a switch operative upon deviation of the gyroscope spin axis from the vertical axis a greater degree than a predetermined maximum to provide a minimum erection rate for the gyroscope, and means for timing the sequence of the erection rate of said gyroscope.

13. A gyro precessing system comprising a gyroscope, means on said gyroscope for developing intermittent signal voltages upon departure of the gyroscope spin axis from a predetermined attitude, means responsive to the signal voltages to intermittently precess said gyroscope, and means for varying the'rate at which said responquence.

GUY F. ROUSI-I.

REFERENCES CITED The following references are of record in the file of this patent:

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